LETM1 couples mitochondrial DNA metabolism and nutrient preference

Abstract The diverse clinical phenotypes of Wolf–Hirschhorn syndrome (WHS) are the result of haploinsufficiency of several genes, one of which, LETM1, encodes a protein of the mitochondrial inner membrane of uncertain function. Here, we show that LETM1 is associated with mitochondrial ribosomes, is...

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Main Authors: Romina Durigon, Alice L Mitchell, Aleck WE Jones, Andreea Manole, Mara Mennuni, Elizabeth MA Hirst, Henry Houlden, Giuseppe Maragni, Serena Lattante, Paolo Niccolo’ Doronzio, Ilaria Dalla Rosa, Marcella Zollino, Ian J Holt, Antonella Spinazzola
Format: Article
Language:English
Published: Springer Nature 2018-07-01
Series:EMBO Molecular Medicine
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Online Access:https://doi.org/10.15252/emmm.201708550
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Summary:Abstract The diverse clinical phenotypes of Wolf–Hirschhorn syndrome (WHS) are the result of haploinsufficiency of several genes, one of which, LETM1, encodes a protein of the mitochondrial inner membrane of uncertain function. Here, we show that LETM1 is associated with mitochondrial ribosomes, is required for mitochondrial DNA distribution and expression, and regulates the activity of an ancillary metabolic enzyme, pyruvate dehydrogenase. LETM1 deficiency in WHS alters mitochondrial morphology and DNA organization, as does substituting ketone bodies for glucose in control cells. While this change in nutrient availability leads to the death of fibroblasts with normal amounts of LETM1, WHS‐derived fibroblasts survive on ketone bodies, which can be attributed to their reduced dependence on glucose oxidation. Thus, remodeling of mitochondrial nucleoprotein complexes results from the inability of mitochondria to use specific substrates for energy production and is indicative of mitochondrial dysfunction. However, the dysfunction could be mitigated by a modified diet—for WHS, one high in lipids and low in carbohydrates.
ISSN:1757-4676
1757-4684